A cephalosporin derivative of the formula I: ##STR1## in which X is S, O, CH.sub.2 or SO, R1 is (optionally-substituted)imidazol-2-yl or one of the C-7 acyl groups known in the cephalosporin art, R2 is hydrogen or methoxy, R3 is carboxy or a biodegradable ester thereof and --R4 is of the formula XII, XIII or XIV: ##STR2## in which R32-R40 inclusive are as defined in the specification; and the salts thereof. Pharmaceutical compositions, methods of manufacture and intermediates are also described.
公式I的
头孢菌素衍
生物:##STR1##其中X是S、O、CH.sub.2或SO,R1是(可选取代)
咪唑-2-基或
头孢菌素领域已知的C-7酰基之一,R2是氢或甲氧基,R3是羧基或其可
生物降解酯,--R4是公式XII、XIII或XIV:##STR2##其中
R32-R40包括如规范中定义的;及其盐。还描述了制药组合物、制造方法和中间体。